[MM 0.7] Bearer properties simplification

[Aleksander Morgado <aleksander lanedo com>]

Hey Nathan & list,

I tried to simplify a bit the handling of the Bearer properties in MM;
the rework is available in the 'bearer-properties' branch in the
following git repo: git://gitorious.org/aleksander/modemmanager.git

Basically, the base MMBearer will keep a MMBearerProperties object
around, the same one received when the bearer is created, and bearer
subclasses are therefore allowed to query each of the properties
directly from there, no need to define the properties separately. E.g,
to get user and password from within a bearer subclass, you can just:

  user = mm_bearer_properties_get_user (
           mm_bearer_peek_config (MM_BEARER (self)));
  password = mm_bearer_properties_get_password (
           mm_bearer_peek_config (MM_BEARER (self)));

Does it sound good? Any additional change that could be done before
merging to git master?

-- 
Aleksander